Problem: Simplify the following expression: $y = \dfrac{-2n + 5}{5n + 9} \div \dfrac{1}{7}$
Dividing by a number is the same as multiplying by its inverse. $y = \dfrac{-2n + 5}{5n + 9} \times \dfrac{7}{1}$ When multiplying fractions, we multiply the numerators and the denominators. $y = \dfrac{(-2n + 5) \times 7} {(5n + 9) \times 1}$ $y = \dfrac{-14n + 35}{5n + 9}$